Nearly one in five teen births is a repeat birth, according to a CDC report. / Jupiterimages, Getty Images

by Sharon Jayson, USA TODAY

by Sharon Jayson, USA TODAY

Nearly one in five births to U.S. teens ages 15-19 is not a first child, says a federal report out today.

Of the 365,000 teens who gave birth in 2010, almost 67,000 (18.3%) have had at least one child before, according to the report from the Centers for Disease Control and Prevention. That's down from 19.5% in 2007. Most were the teen mom's second child (86%).

But more teen moms are using birth control, the report says -- almost 91% used some form of contraception after having had a baby. But just 22% of those used contraceptive methods considered to be "most effective" -- tubal ligation, vasectomy, hormonal implant or intrauterine device (IUD). With those, the report says, the risk of becoming pregnant is less than one pregnancy in 100 users a year. The pill, injectables, the patch and the ring are considered "moderately effective."

"The trend is definitely up both on birth control generally and using the most effective forms of birth control, which we call LARC (long-acting reversible contraception)," says CDC Director Tom Frieden. "What that's telling us is nearly all teen moms want to avoid pregnancy and are taking steps to avoid a repeat pregnancy. But the challenge is only one in five are using the most effective means of doing that."

More than three quarters of sexually active teen mothers used one of the "most" or "moderately effective" contraceptive methods after having a baby; they were more likely than other sexually active teens to use a long-acting method (21.5% vs. 4.5%), the report finds.

"Just having one teen birth is a challenge but having a second can just compound things," says Jennifer Manlove, a senior research scientist who has studied repeat births for the nonprofit Child Trends, based in Bethesda, Md. She was not involved in the CDC's report.

The highest percentages of repeat teen births were among American Indian/Alaska natives (21.6%), Hispanics (20.9%), and blacks (20.4%). The lowest percentage was among whites (14.8%). Texas had the highest percentage of any state (22%) and New Hampshire had the lowest (10%).

In eight states -- Arizona, Arkansas, Georgia, Louisiana, Mississippi, Nevada, Oklahoma, and Texas -- 20% of all teen births were repeats. In seven states -- Connecticut, Maine, Massachusetts, New Hampshire, New York, Vermont, and Wyoming -- less than 15% were repeats.

Manlove says as recently as 1990, 25% of teen births were repeat births. "We have seen a steady gradual decline," she says. "Maybe these long-acting methods are the way to go to reduce repeat teen births in the future."

The CDC report notes that "teens are at a high risk for inconsistent use of methods that are user-dependent (e.g., condoms and oral contraceptive pills)," and that "LARC methods might be a suitable option" since they don't require daily monitoring.

But the report says teens "face a number of barriers to LARC use, including cost, limited availability, lack of provider acceptance for this practice in teens, and teen lack of awareness of these methods."